Mechanical calculating device



June 13, 1933.- F. E. MINER 1,914,034

MECHANICAL CALCULATING DEVICE Filed June 30. 1952 Patented June 13, 1933PATENT OFFICE FLOYD E. MINER, OF CHICAGO; ILLINOIS MECHANICALCALCULATING DEVICE Application filed June 30,

My invention relates to a mechanical device adapted for use inarithmetical calculations. I p

An object of the invention is to provide a small, compact andsimpledevice providing a large range of calculations. p

Other objects include the provision of a device having few parts, onewhich is durable in construction and which is particularly adapted tofacilitate the accurate proportionalcalculations throughout the'scale.

Further objects will appear hereinafter by means of the device disclosedin the drawing forming a part of the specification; and in which; V

Figure 1 is a top plan view of the device having ascale thereon.

Fig. 2 is a partialsectional viewtaken on the line 2-2 of Fig. 1. k VFigs. 3 and 4 are detail perspective views of the indicator armssupports. Referring to the drawing, the base or surface of the deviceis; designated as 10, being relatively flat and which may be of anydesiredfshapc,but for ease of handling I prefer to make it aldisc asshown. Aspiral scale 11 is arranged on the surface of the base 10extending from near its middle portion to the outer periphery. The scalemay be graduated on thesurface by means of etching or by placingaprintedformthereon which may be glued or otherwise secured.

A pinion 12 is provided witha reduced shank portion 13'adapted to extendinto a hole 14; centrally of the base 10 and is riveted to be rigidlyheld thereto with the toothed portion of the pinion. extendingvertically above thebase. I

. The pitch circumference ofthe pinion 12 must be the same as that ofthe lead of the spiral scale 11, so that a rack in mesh with the pinionand rotated one full turn will have one of its ends following the spirallead one full turn. f

- ment with the pinion 12 and slidably mount- 1932. Serial No. 620,137.

ed insupporting members 20 and 21 respectively. I

Supporting members 20 and 21 are disclike members provided with acentral bore 20a and 21a respectively adapted to snugly fit in turningrelation on'the pinion 12. The supporting members '20 and 21 have slots20?) and 21b milled transversely of the bores 20a and 20?) into whichtheindicators'or racks 15 and 16 are slidably mounted and guided 69 inmeshing engagement with the pinion 12.

These supporting members having their bearing surface on the teeth ofthe pinion, are mounted with their milled slots 20?) and 21b in face toface relation, with the racks in the mill-slots and in mesh with thepinion.

At its upper end the pinion 12 is provided with a reduced shank 13awhich is riveted over a washer 23 to securely hold a flat spring 22 inplace on the supporting member 21 exerting a pressure so as tofrictionally hold the members 20 and 21 in contact with each other. Awasher 19 is fitted over the pinion and rests on the base 10 on whichthe supporting member 20 turns to space the member from frictionalcontact with the base.

Each of the indicatorsloand 16 is provided at one end with pointers 15aand 16a respectively adapted to surround one side a of the numerals onthe scale 11, while their other ends are provided with lugs 17 and 18respectively, to limit the radial movement in the other direction. 2

As thus fardescribed, the device comprises a fixed scale having a pairof movable indicators or racks in meshing engagement with a pinion thatis also fixed to the base.

When a predetermined ratio is desired as for example, a ratio of'two toone (as shown in Fig. 1) the arms are turned manually about the pinionuntil one of the pointers of the arms is moved radially and comes intocontact with one of the supporting members, which will limit its inwardmovement, causing the pointer to stop at 100 on the scale. That arm isthen held in that position while i the other arm is turned about thepinion against the frictional pressure of the spring until the numeral200 is reached. The opera] ator may then take hold of either arm and nturn the same in a clock-wise direction about the pinion, and the twoarms will turn together being frictionally held in adjusted relation,until the point is moved to the numher that has been selected to bemultiplied, the arm that was at 200 will indicate the result.

While the arms are being turned about the pinion 12, they will be movedradially in fixed relation with each other as to their set angle.

With a device as above described, it is possible to multiply or divideaccurately and quickly by merely adjusting and turning the arms. Individing, the arms are adjusted in the same manner as for multiplying,the only difierence being, the arms are turned in a counter-clockwisedirection.

I contemplate as being included in these improvements all such changes,variations and departures from what is thus specifically illustrated anddescribed as fall within the scope of the appended claims.

I claim l. A device of the character described, comprising incombination a base having a spiral scale thereon, a pinion in fixedrelation to the base and axially of the spiral scale, a pair ofelongated indicators each having rack teeth thereon, said teeth beingconstantly in mesh with said pinion, said indicators being mounted toswing about the axis of the spiral scale and also with respect to eachother while swinging about said axis, the indicators respectively beingmounted to slide inward and outward radially under the influence of thepinion when the indicators are axially turned.

2. A device of the character described, comprising in combination a basehaving a spiral scale arranged thereon, a pinion in fixed relation tothe base and axially of the spiral scale, a pair of elongated indicatorseach having rack teeth thereon and being constantly in mesh with thefixed pinion, supporting means surrounding said pinion to guide eachindicator, said indicators being movable independently with respect toeach other in the support while in mesh with said fixed pinion.

3. A device of the class described, comprising in combination a basehaving a spiral scale arranged thereon. a pinion fixed to said base andaxially of said spiral scale, a pair ot relatively long racks overlyingsaid scale an d in mesh with the pinion, means surrounding said pinionwhereby one of said racks is connected to turn around the pinion and tocarry the other rack with it, said racks moving radially while in theirturning move ment.

4-. A calculating device comprising a base having a spiral scalearranged thereon, a pinion fixed to said base axially of said spiralsale, a pair of relatively long racks overlying each other and inconstant mesh with the fixed pinion, said racks being movable axiallywith respect to each other and also being mounted for radial movements,guide means pivoted to said pinion whereby said racks are guided forradial and axial movements.

5. A. calculating device comprising a base having a spiral scalearranged thereon, a pinion fixed to said base axially of said spiralscale, a pair of indicators having rack teeth thereon and beingconstantly in mesh with said fixed pinion, said indicators being movablearound the fixed pinion for radial adjustment of said indicators, andsupporting means for each of the indicators whereby one of saidindicators is moved independently of the other.

6. A calculating device comprising a base having a spiral scale arrangedthereon, a pinion fixed to said base axially of said spiral scale, apair of indicators having rack teeth hereon and being constantly in meshwith said fixed pinion, said indicators being movable around said fixedpinion for radial adjustment of said indicators, supporting means foreach of said indicators, and tension means coacting with said supportingmeans for normally holding them together.

7 A calculating device comprising in combination a base, a spiral scalecarried by the base, a pinion in fixed relation to the base axially ofthe spiral scale, the pitch circumference of the pinion being equal tothe lead of the spiral scale, a plurality of indicator arms having rackteeth thereon and severally in mesh with the pinion, the indicatorsbeing mounted to swing around the pinion on the pitch circumferencethereof, each indicator arm having a pointer at one end thereofregistering in the spiral lead, means for maintaining the indicator armsrespectively in their operating position, tensioning means for holdingthe arms vieldably in given relation to each other, and stop means atthe ends of said arms respectively for limiting their radial movements.

8. A calculating device comprising in combin ation a base having aspiral mathematical computation scale thereon, a pinion having its pitchcircumference equal to the lead of the spiral scale andinfixedrelationtothebase and axially central of the scale, a pair ofindicator arms having pointers at one end thereof and rack teethextending their entire length and in mesh with the pinion, theindicators being mounted to swing about the pitch circumference of thepinion, stops at the free ends of said indicator arms to limittheirextreme outward movements respectively, means for maintaining theindicator arms respectively in their operative positions, and tensionmeans coacting with said maintaining means whereby the indicator armsmay swing on and around the pinion.

9. A calculating device comprising in combination a base having a spiralmathematical computation scale thereon, a pinion having its pitchcircumference equal to the lead of the spiral scale, a plurality ofindicator arms having rack teeth thereon and severally in mesh with thepinion, the indicators being mounted to swing around the pinion on thepitch circumference thereof, each indicator a arm having a pointer atone end thereof registering in the spiral lead, means for supporting andguiding each indicator arm in its operative position, and tensioningmeans for holding the indicator arms yieldably in given adjustedrelation to each other Whereby the indicators are movable with eachother 15 and also independently movable of each other While in mesh withthe fixed pinion.

In testimony whereof I have signed this specification.

' FLOYD E. MINER.

